1. Field of the Invention
The present invention relates to a slide cover structure to cover an operation groove in a housing and to a shift lever device which uses the cover, which are used for shifting operation along the operation groove i.e., zigzag operation.
2. Description of the Related Art
A slide cover, for example, as is disclosed in Japanese Utility Model Application Laid-Open No. 64-47430 has been known. That is, as shown in FIGS. 8 to 10, an operation groove 104 of a step shape is formed in a housing fixed to a vehicle body, and a shift lever 106 is extended outward the housing 102 toward the upper direction (illustrated as an arrow "UP") of the vehicle. The shift lever 106 is supported at its lower end so as to be freely movable in the longitudinal direction (the front direction is shown as an arrow "FR.") and in the transverse direction (shown as an arrow "W") of the vehicle so that the shift lever 106 is operated along the operation groove 104.
A slide cover 108 is provided in the housing to cover the operation groove 104 so as not to be able to look in the interior of the housing 102 through the operation groove 104. The slide cover 108 comprises a first cover plate (main cover plate) 110 and a second cover plate (sub-cover plate) 112. The first cover plate 110 is provided within the housing 102 to oppose to the operation groove 104 and is elongated in the longitudinal direction of the vehicle. As shown in FIG. 10, the edge portions of the first cover plate 110 in the widthwise direction thereof (edge portions orthogonal to the longitudinal direction) are supported by guide rails 120 provided on the reverse surface of the housing 102. The first guide plate 110 is slidably movable in the longitudinal direction of the vehicle by being guided by the guide rails 120. An elongated hole 118 elongated in the widthwise direction of the first cover plate 110 is formed at the center in the longitudinal direction of the first cover plate 110. The above-described second cover plate 112 is provided so as to oppose to the elongated hole 118 at the reverse surface side of the first cover plate 110. As shown in FIG. 10, the edge portions in the widthwise direction (edge portions in the direction orthogonal to the longitudinal direction) of the second cover plate 112 are supported by guide rails 122 provided at the reverse surface of the first cover plate 110. The second cover plate 112 is slidably movable guided by the guide rails 122 in the transverse direction of the vehicle.
At the longitudinal direction center of the second cover plate 112, a cylinder 124 projects which passes through the above-described slot 118 to protrude in the upper direction (i.e., "UP" direction) of the vehicle. By moving the second cover plate 112 in the transverse direction of the vehicle, the cylinder 124 can slidably be moved in the slot 118. A shift lever 106 is provided so as to pass through the cylinder 124. When the shift lever is moved in the direction of the longitudinal direction of the vehicle, the first cover plate 110 is moved together with the second cover plate 112 in the same direction (i.e., the longitudinal direction of the vehicle). When the shift lever 106 moved in the transverse direction of the vehicle, only the second cover plate 112 is moved in the same direction (i.e., the transverse direction of the vehicle). Accordingly, the operation groove 104 can be covered by the first cover plate 110 and the second cover plate from the interior of the housing 102, regardless of the moving directions of the shift lever 106.
Here, each of the widthwise edge portions of the first cover plate 110 comprises an upright portion 114 projected upward and a horizontal portion 116 horizontally extended outwards from the top end of the upright portion 114, so as to form a step shape by bending. Each of the horizontal portions 116 is supported by the guide rail 120. When the second cover plate 112 moves in the transverse direction of the vehicle, it moves under the guide rails 120, as illustrated by chain lines in FIG. 8, so that the longitudinal edges of the second cover plate 112 do not interfere with the guide rails 120 and protrude outward from the widthwise edges of the first cover plate 110 (FIG. 8 illustrates the protruded state). Consequently, the dimension in the widthwise direction of the first cover plate 110 can be small. In addition, the first cover plate 110 is flexible and moved through a path (indicated by dashed line in FIG. 8) curved so as to have the center of curvature at the side opposite to the operation groove 104. That is, the path corresponding to the operation groove 104 is in the shape of a gentle arc or a substantially horizontal shape, while the path apart from the operation groove 104 is in the shape of a considerably curved arc so that when the shift lever 106 is moved in the forward direction or in the rearward direction, an accommodating space for end portions of the first cover plate 110 extended largely from the operation groove 102 in these directions owing to the movement of the shift lever 106 can be small.
Meanwhile, in the above-described conventional cover structure, the widthwise edge portions of the first cover plate 110 are stepwisely formed and the horizontal portions 116 are supported by the guide rails 120, and further, the second cover plate 112 is moved under the guide rails 120 so that dimension of the slide cover 108 in the vertical direction, i.e., dimension of thickness becomes larger. For the purpose of reducing the size of shift lever devices, it is required to reduce the dimension of thickness of the slide cover 108. In addition, the presence of the upright portions 114 to form steps at the widthwise edge portions of the first cover plate 110 increases the rigidity and reduces the flexibility of the slide cover.